I usually only run a single instance of XnView w/o activated cache, so I don't have any 1st-hand experience in that regard, but judging from the forum discussions, MP should be capable of negotiating access from more than one “client” simultaniously — even in a network environment.

Most of the time I don't have any problem running multiple instances of MP.
However, I do seem to have issues copying/moving files from one MP to another. I haven't tried to troubleshoot this, though.

Right now I'm stuck with files that won't display, and I have no idea why. I can see them with any other program; just not MP. When I open a "broken" file in another program, say, Imagine (I use it as a plugin in FreeCommander) then it opens it fine. Photoshop opens them fine, too and nothing seems to be wrong with them.

I wonder if MP is trying to automatically correct something in the files and is misplacing a bit somewhere or something like that?
If I open a "broken" file in Photoshop and crop it a teeny bit and then save it, then it fixes the thumbnail in MP but doesn't fix the file itself for MP. That's even weirder.

For the "broken" files, I notice that the Properties tab shows only the "File" part - there is no "Image" information at all - no format, size, dimensions, bits, color model - nothing - not even the section. It's as if MP has decided it isn't an image file, even though it has a thumbnail. However, if I right-click on the broken file and look at the "Properties" in the "Details" tab, there I can see image information such as dimensions.

Ah - now, I tried opening a broken file in XVI32 (a hex editor) and got a file-open error. Where a non-borked file opens fine. So maybe something really is wrong with the file. It would be nice if MP could recognize what this is and repair it. Now if we can just figure out what *this* is.

Brother Gabriel-Marie wrote:Right now I'm stuck with files that won't display, and I have no idea why. I can see them with any other program; just not MP. When I open a "broken" file in another program, say, Imagine (I use it as a plugin in FreeCommander) then it opens it fine. Photoshop opens them fine, too and nothing seems to be wrong with them.

I successfully opened your sample files with two dozen or more programs (including XnView MP). None of them had any problems whatsoever loading these images. Even all the diagnostic software I use on a regular basis (JPEGsnoop, TweakPNG, and Stuffware Photo Studio, to name but a few) gave them a clean bill of health.

So I am using jpegSnoop from your link (I always wanted one of these! thanks!)
I did find a difference between these two files.
The Marker: DHT section has some differences: the Offset is different, and the Huffman Table length is different.
In fact, all three sets of DHT values are different. I don't know if that matters, though. Just thought I'd point it out.

*Something* is different; XVI32 hex editor will open one but not the other. MP likes one, but not the other.

I tried to compare them with AptDiff and get a messagebox-loop, "The parameter is incorrect" and it never lets up.
I selected borked.jpg in one file and good.jpg in the other box and chose "binary" for comparison.
It won't do it. I'm having a bad day at this.

There seems to be a bug in MP's (or Qt's) handling of certain file system features (file junctions, symbolic links, hard links or file streams). Many archiving utilities discard – at least by default – data like attributes, permissions etc. during compression, which might be the reason why I didn't run into problems comparing your files with AptDiff.

Let's hope that Pierre will soon be able to identify the underlying problem and fix it.